Variable-displacement piston



J. SCHAEFFERS. VARIABLE DISPLACEMENT PISTON FOR INTERNAL comausnonmamas.

RPFLICATIUN FILED FEB. 5 \916- 1,319,446, Patented July 22, 1919.

flaw?? 7 M WW 2 Wow 7M M M JOSEPH SCHAEFFEBS, F LAKEWOOD, OHIO.

VARIABLE-DISPIiAGEMENT PISTON FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented July 22, 1919.

Application filed February 5, 1916. Serial N 0. 76,243.

To all whom it may concern:

Be it known that I, JosEPH SOHAEFFERS, a citizen of the United States,residing at Lakewood, in the county of Cuyahoga and State of Ohio, haveinvented a certain new and useful Improvement in Variable-DisplacementPistons for Internal-Combustion Engines,'.of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings.

This invention relates generally to internal combustion engines and moreparticularly to the construction and operation of the piston, the objectof the invention being to greatly increase the efliciency and power ofthe internal combustion engine. With this object in view my inventionconsists in providing in connectlon with the standard type of internalcombustion engine a piston of variable displacement, said piston beingof normal displacement during the intake, compression and firing strokesand of abnormal displacement upon the exhaust stroke whereby all of thespent gases are expelled from the cylinder and thereby enabling a purermixture to be taken in at each intake stroke and the efficiency of theengine correspondingly increased.

I11 the drawings forming a part of this specification I have shown oneembodiment of'my invention and in which Figure l is a vertical sectionalview of an internal combustion engine cylinder with one form of variabledisplacement piston operating therein, said piston being shown of normaldisplacement; and Fi 2 is a similar view showing the parts shi ted sothat the piston will have abnormal displacement.

In the standard forms of internal combustion engines the piston has adefinite stroke and therefore normally has a definite displacementwhereby a definite compression of the gases drawn into the cylinder canbe obtained and con uently after the explosion has taken place t episton on the exhaust stroke moving exactly the same distance as uponthe compression stroke leaves within the cylinder a definite amount ofthe spent gases and this roughly estimated is from one-fifth toone-eighth of the total volume according to the construction of theengine and is sufficient to materially affect the efliciency of theengine and it is With the object of entirely getting rid of all thespent gases that without chan ing or altering any features of the cyliner construction and other parts of the engine except the piston that Ihave devised my variable displacement piston which as before stated isnormally during three cycles of operation and abnormally during theexhausting cycle for the purposes hereinbefore mentioned.

Referring to the drawings A indicates the cylinder of an internalcombustion en ine which as before stated is of the standard or anypreferred type having an inlet valve B and an exhaust valve C andworking within this cylinder is a piston D connected to the crank shaftas usual by the connection E. Upon the inner end of this piston D isarranged a sub-piston F and if desired the main and sub-pistons can bothbe provided with packing rings or if preferred only the sub-piston. Thissub-piston F is movable with reference to the main piston and thismovement may be accomplished by momentum pure and simple or it can beautomatically accomplished or it can be mechanically operated from thecrank shaft or connecting rod or other part of the engine, the manner ofshifting or moving said sub-piston being of minor importance'and in thepresent instance I have shown one form of device for accomplishing thesame, this being a bell crank lever G pivoted at its elbow in the end ofthe main lston and connected at one end to the sub-p1ston and at itsother end to a rod operatively connected to any portion of the engine.The sub-piston can be entirely independent of the main piston or it canbe constructed with skirt portions adapted to fit around or telescopeupon the end of the main piston, but this also is a detail which may bechanged or modified as the necessities require without departing fromthe broad principle of my invention. On the intake stroke the sub-pistonwill be in contact with the main piston so that both main andsub-pistons will produce a normal displacement and upon the compressionstroke the main and sub-pistons will remain in this close or normalcondition so that the normal compression is obtained. During the firingstroke they remain in the same relative positions so that the full forceof the explosion is transmitted to the power shaft. Upon the exhauststroke however the subpiston separates or moves away from the mainpiston and the piston as a whole may be said to expand to its abnormalposition so that upon the compression stroke instead of the pistonhaving a normal displacement as on the compression stroke will have theabnormal displacement and practically fill the entire cylinder volumeand forcing out through the exhaust valve all of the spent gases. Whenthe exhaust stroke has been completed and the intake stroke begun thesub-piston is brought back or assumes its close or intimate relationwith the main piston so that the two together provide a piston of thenormal displacement and the intake compression and firing operations arethen carried on again with the parts in close relation and thereexpanded or abnormal positions or relations are brought about onlyduring the exhaust stroke for the purpose of ridding the cylinder of allof the burnt gases and this complete elimination of all the burnt gasesmaterially increases the efficiency and power of the engine as a Wholeand it will be noted that this increase in cfliciency and power of theengine as a Whole is accomplished by me Without making any alterationwhatever in the engine construction other than the piston and it isobvious that various combinations of pistons and sub-pistons and meansfor relatively moving the two can be employed Without departing from thebroad principle of my invention as covered by the appended claims.

Having thus described my invention, What I claim is:

1. In an internal combustion engine, the combination of a cylinder, amain piston therein, a supplemental piston therein, a connecting rodattached to the main piston,

an extensible connection between said pistons, and actuating meansindependent of the connecting rod and connected between said extensibleconnection and the engine shaft for the purpose described.

2. In an internal combustion engine of the four cycle type, thecombination of a cylinder, a main therein, a supplemental pistontherein, a connecting rod attached to said main piston, saidsupplemental piston being maintained fixed relation to the mam piston,dur'ng the C mpression and power strokes, and means operated from theengine shaft for causing a relative displacement between said pistonsduring the exhaust stroke for the purpose described.

3. In an internal combustion engine of the four cycle type, thecpmbinatipn of a cylinder, a piston thfil'ein, a connecting rod having avariable stroke connection with said (piston, and means actuated fromthe engine shaft for shifting said connection during the exhaust 'ndintake strokes for the purpose described.

4. In an internal combustion engine, a piston having onnection with aconnecting rod, :1 sub piston separate from the main piston, mo ableconnections between said main and sub'pistons and means operable fromthe eng ne shaft for moving said movable connections for the purpose setforth.

In testimony whereof I hereunto aifiX my signature.

.1 OS. .S CHAEFFERS.

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